GEOLOGY AND PALEONTOLOGY OP THE SCHOHARIE VALLEY 195 



nearly 100 feet are exposed in successively outcropping ledges 

 above the Esopus shales. At Borst Mills, a mile above Middle- 

 burg, the Onondaga crosses the Schoharie kill, producing a low 

 fall with ledges visible along the bank. 



Fossils of the Onondaga limestone 

 A complete list of the Onondaga fossils found in the Schoharie 

 region is given in chapter 7. A few of the more characteristic 



■^■:\. 



may be noted here. Of the corals 

 making up the reefs, only a few 

 are cited here and in the list, 

 since no complete study of the 

 coral fauna of the New York 

 Onondaga has been made. The 

 following are abundant : F a v o - 

 sites basalticus [fig. 121, 

 122], most readily recognized 

 by the single, rarely double, row 

 of large mural pores in each wall 

 of the corallites ; F . e p i d e r - 

 m a t u s with two or more rows 

 of mural pores on each face of 

 the corallite separated by faint 



elevated ridges ; Zaphrentis prolifica [fig. 123] , a 

 short curved, hornlike species Avith the septa slightly twisted at 

 the center ; Oyathophyllum robustum, a large, 

 robust, cylindric species with numerous thin septa and an abun- 

 dance of dissepimental tissue. With these occur several species 

 of Dendropora, slender, more or less cj^indric and branching 

 stems with the corallites opening in circular or oval apertures 

 superficially far apart. 



Among the brachiopods the following may be noted : O r t h o - 

 thetes pandora [fig. 124], a reversed strophomenoid shell, 

 slightly unsymmetric, with the pedicle valve moderately concave 

 anteriorly and with radiating striae increased by intercalation 

 and crenulated by concentric striae; Leptaena rhom- 



Fig-. ]26 St ropheodonta 

 inequiradiata 



